P1664: WHICH FACTORS DO IMPACT IN OPTIMAL ANTICOAGULATION IN ANTIPHOSPHOLIPID SYNDROME?
Authors: Juan Luis Ontiveros-Austria, Sergio Rodriguez-Rodriguez, José Manuel Sánchez-Albarrán, Alfonso Orozco, Sofía Ávila Luna, Aldo Alejandro Silva Esparza, Alec Seidman Sorsby, Ana Barrera Bargas, Angel Gabriel Vargas Ruiz, Roberta Demichelis
Journal: HemaSphere (2023)

Topic: 34. Thrombosis and vascular biology - Biology & Translational Research Background: Antiphospholipid syndrome (APS) is the most prevalent cause of acquired thrombophilia. For most individual with APS and a thrombotic event, there is an indication of lifelong anticoagulation with vitamin K antagonists; maintaining therapeutic goals may be challenging, as the influence of several variables is present. In other settings, such as atrial fibrillation, time in therapeutic range (TTR) over 60% that has been associated with better outcomes. Aims: To stablish the rate of TTR as well as factors that are associated with worse INR and TTR control in a cohort of patients with APS. Methods: We retrospectively analyzed a cohort of patients diagnosed with thrombotic APS according to the Miyakis criteria. We analyzed the TTR by the Rosendaal method, as well as by the rate of visits under control over the total of visits to an anticoagulation clinic. Descriptive variables were reported as frequencies and medians; differences between groups were determined by χ2 and Mann-Whitney U test. Correlations were estimated by Pearson. Results: Sixty-one patients diagnosed with APL were evaluated between January 2013 and December 2018; 70.5% were women with a median age of 26 years (14-68 years). Primary APL was diagnosed in 49.2% and the most concurrent disease among secondary APL was SLE. Baseline characteristics are described in table 1. Triple positive antibodies were identified in 39.3%, while cytopenia were detected in 41% of the patients. Most frequent thrombosis sites were deep venous thrombosis (37.7%), arterial thrombosis (31.1%), pulmonary embolism (18%) and splanchnic (13.1%). Median follow-up was 31 months (0.23-157.2 months); mean visits per year were 8.45 (2.37-18); 41% of the patients reported 100% treatment adherence. There was a greater probability of presenting more than 90% of the visits with good treatment adherence among secondary APL versus primary (87.1% vs 63.3%, OR 0.256 (CI95% 0.71-0.926), p=0.04). Mean TTR ratio was 33.3% and by Rosendaal method was 43%; factors associated with TTR ratio over 60% were primary APL (30% vs 6%, OR=6.214 (1.21-31.77) p=0.022) and absence of SLE (28.1% vs 6.9%, OR 0.189 (0.037-0.966) p=0.032). Thrombosis over anticoagulation was developed in 18%, with a median INR at the time of thrombosis of 1.5 (1-2.9). A moderate concordance among Rosendaal method and the TTR ratio by a κ test was determined (κ=0.528, p<0.005). Summary/Conclusion: The TTR by Rosendaal method in our cohort is 43%, which is considerably lower than the 60% recommended. This contrasts with the fact that secondary APL is less commonly controlled than primary APL, which may be associated with the inflammation and complement activation of SLE. It is remarkable that older patients have better treatment adherence, and this may be related with better control. Rosendaal method is a more complicated calculation, but even if the TTR ratio does not evaluates the whole picture, it has an acceptable concordance with the gold standard, and may be useful for monitoring control. A strict control of rheumatologic underlying diseases, as they participate also in anticoagulation control, may be optimal for reaching a better TTR on secondary APL, considering they have a more complicated treatment background and lower TTR than primary APL.Keywords: Autoimmunity, Lupus anticoagulant, Antiphospholipid syndrome, Anticoagulation